000
AXPZ20 KNHC 212132
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 21 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTEND FROM 06N78W TO 
05N100W TO 08N125W TO 07N140W. NO SIGNIFICANT CONVECTION. 

...DISCUSSION...

NEARLY STATIONARY 1030 MB HIGH PRES CENTERED NEAR 39N139W EXTENDS
A SURFACE RIDGE OVER THE FORECAST AREA ROUGHLY N OF 20N W OF 
110W. PRES GRADIENT BETWEEN RIDGE AND LOW PRES ASSOCIATED WITH 
THE ITCZ IS INDUCING AN AREA OF FRESH TO STRONG NE TRADE WINDS W 
OF 130W. MODEL GUIDANCE SUGGESTS THE HIGH WILL WEAKEN AND SHIFT 
NE OVER THE NEXT 24 HOURS...ALLOWING WINDS TO DIMINISH TO BELOW 
20 KT WITHIN 24 HOURS. 

LONG PERIOD NW SWELL GENERATED IN THE CENTRAL PACIFIC ARE 
ALREADY REACHING THE NW PART OF AREA AND WILL CONTINUE TO SPREAD 
SE THROUGH SUN. WW3 WAVE MODEL SHOWS SEAS PEAKING AT AROUND 16 
FT NEAR 30N140W LATE TONIGHT THEN SUBSIDING TO LARGE AREA OF 11 
TO 12 FT SEAS OVER W PORTION OF THE FORECAST REGION BY SUN 
MORNING.

GAP WINDS...
WINDS ARE ON THE INCREASE THROUGH THE GULF OF TEHUANTEPEC AS 
HIGH PRES BUILDS S ACROSS MEXICO AND THE WESTERN GULF OF MEXICO 
IN THE WAKE OF A COLD FRONT THAT CURRENTLY MOVES THROUGH THE 
YUCATAN PENINSULA. IXTEPEC MEXICO IS REPORTING SUSTAINED WINDS 
OF 25 KT WITH GUSTS OF 35 KT. IN ADDITION...VISIBLE SATELLITE 
PICTURES REVEAL A WELL DEFINED ROPE CLOUD MOVING DOWNSTREAM OF 
THE GULF OF TEHUANTEPEC WHICH LIKELY DELINEATES THE LEADING EDGE 
OF THE CURRENT GAP WIND EVENT. THIS WILL BE A BRIEF HIGH WIND 
EVENT WITH WINDS PEAKING AT 25-30 KT TONIGHT THROUGH SAT WITH 
FRESH N WINDS CONTINUING TO PULSE DIURNALLY TO AROUND 36 HOURS.

AN EXPERIMENTAL ASCAT 25 KM COASTAL WINDS SHOWED WINDS OF 20 TO 
25 KT THROUGH THE GULF OF CALIFORNIA N OF 25N. THESE WINDS ARE 
FORECAST TO BE LESS THAN 20 KT IN ABOUT 24 HOURS BUT WILL 
INCREASE AGAIN TO 25-30 KT SUN AFTERNOON AS STRONG HIGH PRES 
BUILDS OVER THE GREAT BASIN REGION. 

$$
GR